Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

With no annotations provided, the description carries the full transparency burden. It discloses that the operation is read-only, free (price 0.0), and uses the NVD CVE API 2.0, which signals safety and cost expectations. It also lists the fields returned (description, CVSS, dates, references). It does not mention rate limits or error behavior, but for a simple lookup these are minor omissions.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Is the description appropriately sized, front-loaded, and free of redundancy?

The description is a single, focused sentence that leads with the primary action and includes essential context (API source, returned fields, read-only status, price). There is no filler or redundant information. Every phrase adds value.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

The tool is simple: one parameter, no output schema, and the description explicitly enumerates the return contents (description, CVSS, published/modified dates, references). It also notes the API provenance and cost. Given the low complexity and high schema coverage, the description is complete for an agent to invoke correctly.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

Schema description coverage is 100%, and the parameter description ('CVE identifier (e.g. CVE-2021-44228)') already explains cveId well. The tool description adds little beyond 'by id', which reinforces the schema. With high schema coverage, a baseline of 3 is appropriate; the description does not degrade or enhance parameter understanding significantly.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Does the description clearly state what the tool does and how it differs from similar tools?

The description uses a specific verb 'Fetch' and identifies the exact resource ('a single CVE record by id'), clearly distinguishing from siblings like cve_lookup_search_cve which searches multiple records. It also explicitly names the API source (NVD CVE API 2.0), leaving no ambiguity about what the tool does.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Does the description explain when to use this tool, when not to, or what alternatives exist?

The description implies the primary use case: when a specific CVE ID is known and a single record is needed. It contrasts implicitly with siblings (search vs. lookup), but it does not explicitly state when not to use it or mention alternatives. The 'by id' phrasing provides clear context for when this tool is appropriate.

Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.